Extreme heat from thermal features at Yellowstone National Park, created by the active volcano below the park, caused oil to bubble on a road surface Wednesday and damage it.Park crews had to close and repair the 3.3-mile loop road that takes visitors past White Dome Geyser, Great Fountain Geyser and Firehole Lake.Blame it on the Yellowstone Volcano.Yellowstone National Park — a UNESCO World Heritage Site — sits atop one of the world’s largest volcanoes, and some of the thermal spots have damaged the popular Firehole Lake Drive. The park features over 10,000 thermal spots, about half the world’s known thermal spots.Although the volcano is active — evidenced by the thermal features and 1,000 to 3,000 earthquakes annually — park officials don’t expect a catastrophic eruption anytime in the next 1,000 or even 10,000 years.Yellowstone’s first supervolcanic eruption occurred 2.1 million years ago, and there were other Yellowstone supereruptions 1.3 million and 640,000 years ago.The park has instruments monitoring the volcano throughout the park, and there would be plenty of warning — weeks or even months — if an eruption were going to occur.In the meantime, enjoy the park! Maintenance crews quickly repaired the road, and it was reopened to visitors Saturday.